发酵强度低是制约液态发酵果醋工业化生产的核心问题。研究表明，依赖于吡咯喹啉醌的乙醇脱氢酶（PQQ-ADH）对醋酸菌的产酸能力具有重要的促进作用。因此，找出代谢活力关键酶的限制机制并开展深入调控具有重要意义。申请人在前期成功构建adhA-adhB过表达突变菌的基础上，拟围绕关键酶PQQ-ADH代谢调控功能及高强度发酵机制开展探索：①关键酶对细胞代谢网络的影响规律研究：对突变菌与原始菌的发酵特性及底物耐受性进行系统研究；分析代谢网络中碳流量、相关酶活力及其基因水平的变化态势，阐述关键酶对醋酸菌产酸能力的作用机制。②基于关键酶的果醋高强度发酵调控研究：重点开展关键酶激活剂及发酵策略的外源调控研究，形成果醋半连续高强度发酵体系；研究半连续发酵特性，着重分析代谢途径相关酶活力和细胞组织对环境聚变的响应，试图揭示果醋高强度发酵机理。研究结果期望为果醋的高强度液态发酵提供一定参考。

Low productivity is the core issue that restricts the industrial production of fruit vinegar by liquid fermentation. Studies have shown that pyrroloquinoline quinine-dependent ethanol dehydrogenase (PQQ-ADH) plays an important role in promoting the ability of acetic acid production by Acetobacter. Therefore, it is a great significance to find the restriction mechanism of the key enzyme to the metabolic activity and regulate the metabolic activity of key enzyme by metabolism control. In the previous research, the adhA-adhB overexpression mutant has been successfully constructed, in order to explore the metabolic regulation function and the fermentation mechanism for high productivity，the applicants propose to carry out the following researches around the key enzyme PQQ-ADH: ① Studying the influence of the key enzyme on the metabolism network of Acetobacter: To state the functional mechanism of key enzyme on acetic acid production ability of Acetobacter, the fermentation characteristics and the substrate resistance ability of the mutant and the wild-type strain is contrastive analyzed scientifically; the changes of carbon flux, relevant enzymes activity and their gene expression level in the metabolic pathway, is also analyzed. ② Studying the metabolic regulation strategy of the key enzyme for fruit vinegar fermentation with high productivity: To obtain the semi-continuous fermentation system of fruit vinegar production with high productivity, the influnce of the key enzyme activator and the fermentation strategy on the ability of acid production are focused on; To reveal the mechanism for fruit vinegar fermentaiton with high productivity, the characteristics of the semi-continuous fermentation are studied, and the stress situation to the extreme environment of the relevant enzymes activities in metabolic network and the cell tissues are emphatically analyzed. The results are expected to provide certain reference for the fruit vinegar production by liquid fermentation with high productivity.